🚩(back) use existing no websocket feature flag

An already existing feature flag
COLLABORATION_WS_NOT_CONNECTED_READY_ONLY was used bu the frontend
application to disable or not the edition for a user not connected to
the websocket. We want to reuse it in the backend application to disable
or not the no websocket feature.

src/frontend/apps/e2e/__tests__/app-impress/common.ts

@@ -6,7 +6,7 @@ export const CONFIG = {
   AI_FEATURE_ENABLED: true,
   CRISP_WEBSITE_ID: null,
   COLLABORATION_WS_URL: 'ws://localhost:4444/collaboration/ws/',
-  COLLABORATION_WS_NOT_CONNECTED_READY_ONLY: false,
+  COLLABORATION_WS_NOT_CONNECTED_READY_ONLY: true,
   ENVIRONMENT: 'development',
   FRONTEND_CSS_URL: null,
   FRONTEND_HOMEPAGE_FEATURE_ENABLED: true,